Ifni Glacial Lake (Western High Atlas): Genesis and last glaciation heritage

The reliefs overlooking the valleys of the Western High Atlas were covered by glaciers at the level of cirques. The footprints of the glacier activities are characterized in this region by moraines, boulders and ridges. The geomorphological observations show that the Ifni lake, located in the east of Toubkal Mountain, is formed by a natural dam that we interpret as glacial activity. The mixed volcanic lithologies of moraine are consistent with erosion and transport from various points in the valley, which is formed in a suite of lavas: rhyolite, ignimbrite, andesite and basalt.During part of the Holocene and during the little ice age, the glacier has built a moraine of over 130 m in height, which  was built in the form of three main ridges separated by depressions. The amalgamation of the moved unities and their position in steps could lead their interpretation as marks of the succession ofthree main stages of glacier advance and retreat during pulses of short duration

Hydro-climate characteristics of the karst system of Wintimdouine cave (Western High Atlas, Morocco): monitoring and implications for paleoclimate research

The cave of Wintimdouine, located in a semi-arid context in Morocco, comprises the longest-known underground river in Africa. This cave system faces many challenges related to anthropogenic and climate forcing. Therefore, it has become necessary to understand the functioning of the aquifer system of Wintimdouine and how the regional climate affects its environment. Herein, we used different approaches based on a 4-year monitoring to shed light on the hydro-chemical behavior and stable isotopes contents of water samples, climate settings inside the cave, and moisture trajectory analyses. Chemical analyses show that groundwater is dominated by bicarbonate and calcite with an excellent chemical quality of cave water, suggesting an active recharge of the aquifer system which constitutes the main drinking source in the region. The stable isotope composition is consistent among rainwater, cave water and groundwater samples outside the cave. The evaporation effect is not significant, probably due to the rapid infiltration of surface water to the epikarst and vadose zone, which is favored by the abundance of exo-karstic forms above the cave. The cave monitoring indicates that periods of increased drip water flow induce an increase of temperature and humidity inside the cave, mainly during the spring-summer season. The high relative humidity and the relatively stable temperature favor the carbonate deposition under equilibrium conditions with drip water inside the cave. Furthermore, the moisture trajectory analysis confirms that the predominant air masses reach Wintimdouine cave from the North Atlantic Ocean, consistent with the mean deuterium-excess value of rainwater samples and the NAO-related westerly winds. Hence, we highlight the potential of Wintimdouine speleothem delta O-18 as a proxy of past climate variability at a regional scale

Flood Hazard Index Application in Arid Catchments: Case of the Taguenit Wadi Watershed, Lakhssas, Morocco

During the last decade, climate change has generated extreme rainfall events triggering flash floods in short periods worldwide. The delimitation of flood zones by detailed mapping generally makes it possible to avoid human and economic losses, especially in regions at high risk of flooding. The Taguenit basin, located in southern Morocco, is a particular case. The mapping of the flood zones of this basin by the method of the Flood Hazard Index (FHI) in a GIS geographic information systems environment was based on the multi-criteria analysis, taking into consideration the seven parameters influencing these extreme phenomena, namely rainfall, slope, flow accumulation, drainage network density, distance from rivers, permeability, and land use. Average annual rainfall data for 37 years (1980 to 2016) was used in this study for floodplain mapping. A weight was calculated for each parameter using the Analytical Hierarchy Process (AHP) method. The combination of the maps of the different parameters made it possible to draw up a final map classified into five risk intervals: very high, high, moderate, lower and very lower presenting, respectively, 8.04%, 20.63%, 31.47%, 15.36%, and 24.50% of the area of the basin. The reliability of this method was tested by a Flood susceptibility analysis. The results generated by the Flood Hazard Index (FHI) model are similar to those of previous historical events. Realistic and applicable solutions have been proposed to minimize the impact of these floods as much as possible